Opiate users making initial contact with methadone treatment are at risk of injection-related and sexual transmission of HIV disease and are at higher risk if placed on a waiting list than it treatment availability was unlimited. The purpose of the project is to develop and test a theory- driven brief motivational intervention targeting injection-related and sexual risk behaviors for this population. Motivational Enhancement (ME) techniques (Miller & Rollnick, 1991) offer the advantages of brevity, feedback to clients that is specific to the cognitions and behaviors placing each person at risk, and use of the person's own ambivalence to motivate change. Elicitation research will be first be conducted via ethnographic interviews with 40 methadone waiting list clients to identify salient perceived consequences of risk behaviors, normative referents important to this population, and perceived facilitators of, and barriers to, behavior change. This information will be used to select and revise assessment tools to be used in a ME intervention. These tools will then be pretested with an additional 20 waiting list clients to determine whether they are readily understood, elicit a range of responses and can be used to give feedback to clients regarding their motivation and risk status. An ME intervention will then be tested in a randomized 1 X 3 partial repeated measures design in which 249 waiting list clients are assigned, 83 to ME, 83 to an Assessment-Only (AO) group, and 83 to an Assessment-at-Follow-up- Only (AFO) group. Follow-up interviews will be conducted at 1 and 3 months and will include assessment of drug use, injection and sexual risk behaviors, intentions to engage in these behaviors, outcome beliefs and norms regarding these behaviors, stage of change, and self-efficacy to engage in protective behavior. It is hypothesized that the ME group will be less likely than the other two groups to engage in high risk sexual and injection behaviors at follow-up, will have beliefs and intentions less favorable to risk behavior, will have progressed in terms of stage of change related to risk behavior, and may, because of an increase in self- efficacy, be less likely than the other two groups to drop from the waiting list prior to treatment entry.